Oil circulation in an electric submersible pump (ESP) electric motor

Patent metadata

Field	Value
Publication number	US-11739619-B2
Application number	US-202117530714-A
Country	US
Kind code	B2
Filing date	Nov 19, 2021
Priority date	Nov 19, 2021
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

An electric submersible pump (ESP) electric motor. The ESP electric motor comprises a housing; a stator retained within the housing; a drive shaft; and an at least one rotor mechanically coupled to the drive shaft and located concentric with and inside of the stator, wherein an inside surface of the stator defines a groove extending from an upper end to a lower end of the stator, an outside surface of the at least one rotor defines a groove extending from an upper end to a lower end of the at least one rotor, an inside surface of the at least one rotor defines a groove extending from an upper end to a lower end of the at least one rotor, or an outside surface of the drive shaft defines a groove extending from below an male splines at an upper end to a lower end of the drive shaft.

First claim

What is claimed is:

1. An electric submersible pump (ESP) electric motor, comprising:
a motor housing;
a stator retained within the motor housing;
a drive shaft defining a first keyway;
an at least one rotor located concentric with and inside of the stator, wherein an inside surface of the at least one rotor defines a second keyway, wherein (A) the inside surface of the at least one rotor defines a groove extending from an upper end to a lower end of the at least one rotor or (B) an outside surface of the drive shaft defines a groove that extends from an upper portion of the drive shaft adjacent an upper end of the at least one rotor to a lower portion of the drive shaft adjacent a lower end of the at least one rotor; and
a key inserted in the first keyway and in the second keyway that mechanically couples the at least one rotor to the drive shaft,
wherein an inside surface of the stator defines a groove extending from an upper end to a lower end of the stator or an outside surface of the at least one rotor defines a groove extending from an upper end to a lower end of the at least one rotor.

2. The ESP electric motor of claim 1 , wherein the groove in the inside surface of the stator extends helically from the upper end to the lower end of the inside surface of the stator or the groove in the outside surface of the at least one rotor extends helically from the upper end to the lower end of the outside surface of the at least one rotor.

3. The ESP electric motor of claim 1 , wherein the inside surface of the stator defines a plurality of grooves extending from the upper end to the lower end of the stator.

4. The ESP electric motor of claim 1 , wherein the outside surface of the at least one rotor defines a plurality of grooves extending from the upper end to the lower end of the at least one rotor.

5. The ESP electric motor of claim 1 , wherein an inside surface of the at least one rotor defines a plurality of grooves extending from the upper end to the lower end of the at least one rotor.

6. The ESP electric motor of claim 1 , wherein an upper end of the drive shaft defines male splines and an outside surface of the drive shaft defines a plurality of grooves extending from a point less than 1 foot below the male splines to a lower end of the drive shaft.

7. The ESP electric motor of claim 1 , wherein the inside surface of the at least one rotor defines a helical groove extending from the upper end to the lower end of the at least one rotor and wherein the key defines notches where the helical groove meets the key.

8. An electric submersible pump (ESP) electric motor, comprising:
a motor housing;
a stator retained within the motor housing;
a drive shaft defining a first keyway;
an at least one rotor located concentric with and inside of the stator, wherein an inside surface of the at least one rotor defines a second keyway, and wherein (A) the inside surface of the at least one rotor defines a groove extending from an upper end to a lower end of the at least one rotor or (B) an outside surface of the drive shaft defines a groove that extends from an upper portion of the drive shaft adjacent an upper end of the at least one rotor to a lower portion of the drive shaft adjacent a lower end of the at least one rotor; and
a key inserted in the first keyway and in the second keyway that mechanically couples the at least one rotor to the drive shaft.

9. The ESP electric motor of claim 8 , wherein the groove is substantially parallel to a longitudinal axis of the at least one rotor or substantially parallel to a longitudinal axis of the drive shaft.

10. The ESP electric motor of claim 8 , wherein the inside surface of the at least one rotor defines a plurality of grooves.

11. The ESP electric motor of claim 8 , wherein the outside surface of the drive shaft defines a plurality of grooves.

12. The ESP electric motor of claim 8 , wherein the groove is between 0.01 inch deep and 0.03 inch deep.

13. The ESP electric motor of claim 8 , wherein the groove is between 1/16 inch wide and ¼ inch wide.

14. The ESP electric motor of claim 8 , wherein the key defines notches where the groove meets the key.

15. A method of lifting reservoir fluid in a wellbore to a surface location, comprising:
assembling an electric submersible pump (ESP) assembly at a wellsite, wherein the ESP assembly comprises a production pump and an electric motor, where at least one of an inside surface of a rotor of the electric motor or an outside surface of a drive shaft of the electric motor defines at least one groove, where the inside surface of the rotor defines a first keyway, where the outside surface of the drive shaft defines a second keyway, where a key inserted in the first keyway and the second keyway mechanically couples the rotor to the drive shaft, and where the drive shaft of the electric motor is coupled to a drive shaft of the production pump;
coupling the ESP assembly to a production tubing string;
running the ESP assembly into the wellbore at the lower end of the production tubing string;
providing electric power to the electric motor;
turning the drive shaft of the electric motor by the rotor of the electric motor;
turning the drive shaft of the production pump by the drive shaft of the electric motor;
lifting reservoir fluid in the wellbore by the production pump up an interior of the production tubing to the surface; and
circulating oil within the electric motor via the at least one groove defined by the inside surface of the rotor of the electric motor or the outside surface of the drive shaft of the electric motor.

16. The method of claim 15 , wherein the ESP assembly further comprises a gas separator assembly between the electric motor and the production pump.

17. The method of claim 16 , wherein the ESP assembly further comprises a charge pump assembly between the electric motor and the gas separator assembly.

18. The method of claim 15 , wherein circulating the oil within the electric motor comprises circulating the oil via a bore in the drive shaft of the electric motor that is concentric with a longitudinal axis of the drive shaft of the electric motor.

19. The method of claim 18 , wherein the electric motor comprises a bushing retained by the stator of the electric motor and a bearing coupled to the drive shaft of the electric motor and located within the bushing, and wherein circulating the oil within the electric motor comprises circulating the oil via a plurality of passageways defined by the bushing.

20. The method of claim 15 , wherein the ESP assembly further comprises a seal section between the electric motor and the production pump, wherein the seal section comprises a seal section drive shaft, the drive shaft of the electric motor is coupled to the drive shaft of the seal section, and the drive shaft of the seal section is coupled to the drive shaft of the production pump.

Assignees

• Halliburton Energy Services Inc

Inventors

• Sheth Ketankumar Kantilal
• Brown Donn J
• Zheng Dezhi
• De Long Robert Charles

Classifications

• E21B43/128 Primary

  Adaptation of pump systems with down-hole electric drives · CPC title

• E21B47/06

  Measuring temperature or pressure · CPC title

• F04B47/08

  the motors being actuated by fluid · CPC title

• F04D13/10

  adapted for use in mining bore holes · CPC title

• F04B47/06 Primary

  having motor-pump units situated at great depth · CPC title